WhatsApp has introduced Touch ID and Face ID on iPhones. WhatsApp says this will prevent someone “from taking your phone and reading your messages”.
Step 1
To enable this feature, go to Settings on the WhatsApp app.
Step 2
Click on Account, and then on Privacy
Step 3
Click on Screen Lock
Step 4
Turn on Touch ID or Face ID
WhatsApp gives the option to select the time before Touch ID or Face ID is prompted after the WhatsApp app is closed.
WhatsApp says the feature is available only on iPhones, that too only on iPhone 5s or later and on iOS 9.